Middle School STEM Science Lab/Activity Planner
Name of Lab/Activity:Finding the Density of Acrylic Rods / Grade:
8th
California Science Standard(s): (please copy and paste standards taught during this lesson)
7c. Students know substances can be classified by their properties, including their melting temperature, density, hardness, and thermal and electrical conductivity.
8a. Students know density is mass per unit volume.
8b. Students know how to calculate the density of substances (regular and irregular solid and liquids) from measurements of mass and volume.
9f. Apply simple mathematic relationships to determine a missing quantity in a mathematic expression, given the two remaining terms (including speed = distance/time, density = mass/volume, force = pressure × area, volume = area × height).
Learning Objective/Goal:
SWBAT know that the density of a substance does not change no matter the same size.
SWBAT understand that substances can be classified by their properties, which includes density.
SWBAT understand that density is mass per unit volume.
SWBAT calculate the density of substances from measurements of mass and volume.
SWBAT apply simple mathematic relationships to determine the density in a mathematic expression, given the two remaining terms, mass and volume.
Language Objective/Goal: (based on California Common Core Standards)
LA.8.W.2.3.d Organize and display information on charts, maps, and graphs.
WHST.6-8.1.Write arguments focused ondiscipline-specific content. Support claim(s) with logical reasoning and relevant, accurate data and evidence that demonstrate an understanding of the topic
Materials & Resources for Each Lab Group: 5 acrylic cylinders of differing lengths, a 100 mL graduated cylinder, a triple beam balance, a metric ruler, calculator, water
Procedure: A worksheet guides the student groups (2-3 students/group). Students measure the mass and volume of each cylinder and record the values on the data table. This data is graphed and the resultant slope, representing the density, is calculated. Students determine the mass of each cylinder by dividing its mass by its volume. Percent error analysis follows based on the actual density value of acrylic material.
Students are provided with calculators to assist them in mathematical calculations. / Teaching Notes: (include timing) Students should be instructed to measure the mass and then find the volume of the same acrylic cylinder. Review how to find the volume of a cylinder by displacement of water and by ruler measurement.
Prior to the lab a short multimedia lesson by the ACS (American Chemical Society) can be shown to students that explains volume determination by water displacement. This simple straightforward presentation can be found at the URL: http://www.middleschoolchemistry.com/multimedia/chapter3/lesson2
Review how to use the TTB.
Extension Questions: 1. How can we use density to help us identify matter? 2. What is a characteristic property? 3. Is density a characteristic property?
Math Connection: Students determine the volume a cylinder by careful measurement and then use of the formula V= 2πrh. Students find the mass of the cylinder by correctly reading the scales of the triple beam balance.
Students find the density of each cylinder using the formula D=mV.
Students graph their data. The resulting mass vs. volume graph shows plotted points that approximate a straight line with a slope that is the density of the acrylic material. / Teaching Notes:
Technology Extension of Learning: Student drawings and a density song by Willy Banta will be uploaded and shown on YouTube. / Teaching Notes:
Formative Assessment: (please attach a copy)
Short quiz based on Phet density simulation / Teaching Notes:
URL: http://phet.colorado.edu/sims/density-and-buoyancy/density_en.html
Strategies for EL and Special Needs Students: Heterogeneous grouping of students, word walls, realia, sentence starter worksheet / Vocabulary: density, volume, mass, graduated cylinder, triple beam balance, grams, milliliters, g/mL, g/cm3, best fit line, slope, graph, interpolate, extrapolate,
Alignment in science unit: (Brief description of lessons taught prior to & after this lab/activity)
Students have a basic knowledge of the concept of density. They understand that liquids in a density column are aligned according to increased density from top to bottom. They have completed a worksheet on finding the density of various substances. They have completed the activity “Mystery Canisters” (attached).
Brief description of lessons taught after this lab/activity: Students are asked: “Do you think that different samples of the same substance always have the same density? Does the density of a substance help determine the identity of the substance?”
A worksheet that involves determining the density of an unknown substance and then identifying the substance.
Lab/Activity adapted from: (website, textbook, etc.) / Formative Assessment adapted from:
This lesson was developed by:
Teacher’s Name / Currently Teaching at: (School & District)
Nancy Frizzell / South Valley Middle School Gilroy, Unified High School District
This project has been made possible in part by a grant from the Texas Instruments
Community Fund, an advised fund of Silicon Valley Community Foundation.
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